1. Field of the Invention
The invention pertains to an object-support column with a vertical tube, which has a bottom support piece at one end and a guide sleeve installed in the other end. A gas spring coaxially installed in the vertical tube includes a cylinder filled with pressurized gas, the cylinder being divided by a piston into a first and a second working chamber, where one end of the piston rod is attached to the piston, whereas the other end passes through the second working chamber in a sealed manner to the outside, where it is attached to the bottom support piece. An object on which force can be exerted can be mounted on the end of the cylinder projecting out of the vertical tube, and a connection between the first working chamber and the second working chamber can be blocked by a manually openable valve.
2. Description of the Related Art
In object-support columns of this type, it is known that a piston rod which has moved into its outward-extended position can be moved back into the cylinder again by opening the manually actuated valve and exerting force on the column. Conversely, when there is no load on the object-support column, a piston rod located within the cylinder can be allowed to travel outward by opening the manually actuated valve.
Object-support columns of this type are used especially as chair columns, where the height of the chair seat can be adjusted in a continuously variable manner.
After the seat has been adjusted to a height which is lower than the maximum possible height, this height will be retained after the occupant has left the chair until it is adjusted again manually.
If a large number of these chairs are present in a room and if they have been set to a position lower than their maximum height, an unattractive picture is created if they are not returned to that maximum height.
To change this situation, that is, to ensure that the chairs create a uniform picture, it would be necessary to adjust manually each individual chair back to its maximum height, which would require a great deal of effort.
On the other hand, if the occupant leaves the chair for only a short period of time, he should, upon returning to the chair, be able to find the chair still at the previously selected height and not be required to adjust it again.